2.2L whirring clicking noise when cold

I have been having this problem for a week now, and can't seem to narrow it down. It is a 2000 S-10 2.2L Auto. / 64k miles. When the engine is cold (not necessarily temp outside) I hear a whirring, clicking noise like it is a vaccum or intake noise.
But never fails when engine warms up and gets to ~900 - 1000 rpms it stops. I have already checked all my hoses, listened on top of the engine and bottom and watched with a shoplight.
Any ideas?

timeing belt?

timeing belt?

How do I check that, without taking everything apart?

take a long screw driver and put it on something (somewhere you think the noise is commen from that is not electric ie alternater) and stick your ear on the end, and see if you hear the same sound, if not thats not the sorce of the noise

Still having this problem. Changed alternator and air charge temperature sensor (sensor on air tube near air filter box). If I unplug the air temperature sensor near air filter box and start the truck it doesnt make the noise at all. If I plug it back in to the new or used sensor, it starts making the vaccum noise.
Also had it checked for codes, and had none. Check all fuses as well.
Any help would be appreciated.